In air-conditioned vehicle seats or other seating accommodations having air-circulating layers in the region of seat and/or backrest contact surfaces, the problem often arises in the case of stitched seat covers that the regions of a seat or backrest surface separated from one another by stitchings are unevenly air-conditioned, since the flow connection through the cover stitching furrow is insufficient.
In the current state of the art, implementation of cover stitching furrows through a ventilation layer of a knitted spacer fabric is not feasible, either visually or in terms of air-circulation technology. Neither 90° angles nor smooth cushion edges can be formed using known spacer media, so that furrows and cover edges that are made using spacer media do not have a neat appearance. A generally common procedure is to place spacer fabric only in furrow-free regions of the seat and ventilate seat-region surfaces separated from one another by stitching furrows separately from one another in each instance, for example by miniblowers.
U.S. Pat. No. 6,619,737 discloses an air-conditionable vehicle seat which has a ventilation layer, through which air is able to flow, located under a cushion part, as well as an air-permeable upper cushion layer located over this ventilation layer. The cushion is covered with a cushion cover and provided with stitching, along which the cushion cover is connected by fastening means with the upper cushion layer. The ventilation layer extends all the way into the side pieces of the cushion so that the side pieces of the cushion subdivided by stitchings of the seat surface can likewise be supplied with air by the blower for the seat surface for ventilation of the seat. At the same time, in order to obtain a sufficient supply of air for the side pieces, the ventilation layer in the region of the stitchings has a thickness that is almost unchanged.
A vehicle seat of the type mentioned in U.S. Pat. No. 6,619,737, which has a cushion cover with stitchings, is additionally disclosed in U.S. Pat. No. 6,817,675. Here a cushion cover and an upper cushion layer are fastened along the stitchings by fastening means, also bridging the ventilation layer at a lower cushion part. In both of the cases mentioned, a plurality of blowers is used for ventilation of all seat regions.
In addition, an air-conditionable vehicle seat is disclosed in WO 03/101,777 A1. In this case, an air-circulating layer with additional vertical channels is provided, in order also to supply the air-circulating layer with sufficient air-conditioned air through stitched regions of the cover material.